starfish entry

A starfish is basically a kind of clam/oyster beds who eat many clams in a single day. The echinoderms has 3 layers. The third layer of the echinoderms has cilitaed cells, The outer most layer has one layer ofcells that covers spines, the dermis, which is called the middle layer has connective tissue and has the exoskeleton. The exoskeleton helps support the entire spine. The water system in the echinoderm first opens to the madreporite which leads to the stone and then to the ring canal. The canals connect to each arm and it has 5 canals. The gut has a unique u shape. They use their tube feet for gas exchanges. They contain a open circulatory system although it is very less defined. They contain tube feet that utilizes locomotion, the exchange of gases, and feeding. Their sexual reproduction involves males and females that otften release gametes into the water to fertilize. This kind of fertilization is called external fertilization

Astroidea:

Crinoidea:
ophiocistoidea:


echinoidea:

Holothuoidea:
http://www.earthlife.net/inverts/echinodermata.html
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